In general, color images obtained by photographic processing of a silver halide color photographic material are composed of azomethine dyes or indoaniline dyes which are formed by a reaction between an oxidation product of an aromatic primary amine developing agent and a coupler. Color photographic images thus obtained are not necessarily stable to light or humidity and heat, and when they are exposed to light for a long period of time or preserved under conditions of high temperature and high humidity, color fading or discoloration of dye images occurs and the color images deteriorate.
Such deterioration of color image is a serious defect for recording materials. Therefore, in order to preserve semipermanently records formed from color photographic light-sensitive materials, it is desired that the three-color balance in fading of yellow, magenta and cyan dye images necessary to form color images maintain the initial color balance, as well as that such light fading and dark fading are reduced to the extent possible. However, the degree of light fading and dark fading of yellow, magenta and cyan dye images are different from each other and thus, the three-color balance in fading of yellow, magenta and cyan dye images is destroyed, resulting in disadvantageous degradation of image quality of dye images during preservation for a long period of time.
Although the degree of light fading and dark fading is naturally different depending on color couplers employed and other factors, in many cases dark fading occurs in the order of cyan dye images, yellow dye images and magenta dye images, and the degree of dark fading in cyan dye images is particularly large as compared with those in other dye images. On the other hand, light fading tends to occur in the order of cyan dye images, yellow dye images and magenta dye images, particularly in the case of a light source emitting a large amount of ultraviolet light.
Therefore, it is required to prevent light fading and dark fading of cyan dye images as much as possible in order to maintain the three color balance in fading of yellow, magenta and cyan dye images for a long period of time. For the purpose of preventing light fading and dark fading of dye images, various proposals have been made. For instance, many methods are known for obtaining fast dye images by modification of the coupler structure as described, for example, in U.S. Pat. Nos. 2,369,929, 2,772,162, 2,801,171, 2,895,826 and 3,767,412, JP-B-49-1572 (the term "JP-B" as used herein means an "examined Japanese patent publication"), JP-A-50-112038 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), JP-A-53-109630, JP-A-55-163537, JP-A-56-104333, JP-A-59-65844, JP-A-60-205447, JP-A-60-209735, and JP-A-61-39044. However, although these couplers have improved durability, only a small number of these couplers exhibit improvement in both light fastness and heat fastness, and the improvement is still insufficient, taking other photographic characteristics into consideration.
As another method for preventing fading due to light or heat, it is proposed to employ an ultraviolet light absorbing agent or a color fading preventing agent. There are known, for example, hydroquinones, hindered phenols, catechols, gallic acid esters, aminophenols, hindered amines, chromanols, hydroxy coumarans, indanes, ethers or esters formed by sililation, acylation or alkylation of the phenolic hydroxy groups of these compounds, and metal complexes as described in U.S. Pat. Nos. 3,935,016, 3,982,944 and 4,254,216, British Patent 2,066,975, U.S. Pat. Nos. 3,700,455, 4,360,589 and 3,457,079, JP-B-56-21144, U.S. Pat. Nos. 3,336,135, 4,268,593, 4,050,938, 4,241,155, 3,432,300, 3,574,627, 3,573,050, 4,155,765, 4,264,720, 3,764,337 and 4,174,220.
These compounds may have the effect of preventing color fading and discoloration of dye images, but since the effect is insufficient, and the use of these compounds changes the hue, forms fog, causes poor color formation, causes poor dispersibility, and causes fine crystals after coating silver halide emulsions, overall excellent effects for color photography have not yet been obtained by the use of these compounds.
Furthermore, most of these compounds do not improve the fastness of cyan or yellow images to light or heat, although they improve the light fastness of magenta images.
As the result of various investigations, it has been found that fastness of color images to light and heat can be remarkably improved by incorporating an organic synthetic polymer into a color photographic light-sensitive material. However, it is also found that, when the organic synthetic polymer is incorporated into a color photographic light-sensitive material as an additive, color stain occurs in the white background instead of fading of the color images during preservation after development processing, and the degree of color stain is higher than when the organic synthetic polymer is not employed. As the result of further extensive investigation, it is clear that such color stain is different from known yellow stain ("Y-stain") based on decomposition of couplers, and that the color stain is caused by components of processing solutions, particularly an aromatic primary amine compound as a developing agent and a compound derived therefrom, remaining in the photographic materials after development processing.
For the purpose of preventing the occurrence of such color stain, the use of certain amine compounds is described, for example, in U.S. Pat. Nos. 4,463,085 and 4,483,918, JP-A-59-218445 and JP-A-59-229557. However, these compounds are insufficient to achieve the above described purpose. In addition, many of these compounds remarkably reduce the improved fastness of color images which is attained by the addition of the organic synthetic polymer to photographic light-sensitive materials.
It is also known to employ a color fading preventing agent for the purpose of preventing yellow stain due to decomposition of couplers. However, these color fading preventing agents are almost ineffective to prevent the color stain associated with polymer additives although their effect on the prevention of yellow stain ("Y-stain") is recognized.